Match ends, Brighton and Hove Albion 1, Arsenal 1.
Brighton ended a run of three consecutive defeats by holding a disjointed Arsenal to a draw at the Amex Stadium.
Pierre-Emerick Aubameyang curled in the opening goal following fine work from Alexandre Lacazette after just seven minutes.
The Gunners dominated the opening half hour and the Seagulls required two superb saves from goalkeeper Mat Ryan on Aubameyang to stay in the game.
Arsenal right-back Stephan Lichtsteiner then made a poor mistake, heading a long ball into the path of Brighton striker Jurgen Locadia, who rounded Bernd Leno to equalise on 35 minutes.
Mesut Ozil was replaced at half-time but the visitors failed to regain their early composure and rarely tested Brighton's defence.
The hosts pressed for a winner, catching out a ragged Arsenal on the counter-attack, but Locadia and Solly March both missed promising chances.
Arsenal remain fifth in the table, but are now two points behind Chelsea, who beat Watford 2-1 on Wednesday night.
A statement substitution?
Arsenal boss Unai Emery and Ozil have had a curious relationship this season and the decision to substitute the midfielder for Alex Iwobi at half-time will only add to that intrigue.
Emery recently insisted Ozil has a future at the club and the former Germany international responded with an inspirational performance in victory over Burnley but could not exert the same influence here.
Yet he did not play badly and was far from the biggest reason why Arsenal let Brighton back into the game after a commanding opening spell.
Ozil may not have tracked back from the corner that led to Brighton's goal but the poor positioning of Arsenal's centre-backs and Lichtsteiner's woeful header from Davy Propper's speculative pass were more culpable.
Lichtsteiner was fortunate to not be replaced - his passing accuracy below 60% for much of the game before a late recovery to finish on 69.6%.
And without Ozil in the second half, Arsenal lacked creativity and were still vulnerable to Brighton's counter-attacks, resulting in Emery using all of his substitutions by 70 minutes as Aaron Ramsey and Ainsley Maitland-Niles were sent on for Lacazette and Laurent Koscielny respectively.
Even then, Arsenal's best openings only came from Brighton mistakes or by accident - an attempted clearance deflecting narrowly wide off Iwobi late on.
Emery appears to want to challenge Ozil and has made shrewd substitutions to help his side surge in the second half but Iwobi did very little in Ozil's place and removing the German was perhaps the wrong call here.
Brighton recover after worrying start
After relatively narrow defeats by Burnley, Chelsea and Bournemouth in recent weeks, it felt like Brighton would slip to a far heavier fourth-straight loss here in the early stages.
The Seagulls could not keep hold of the ball - Arsenal nearing 85% possession after the first 20 minutes - and their defence showed frequent lapses in concentration, allowing the Gunners to regularly carve through.
For the opener, Lacazette charged down a clearance and won the ball back in the area, holding off three Brighton defenders before flicking the ball on for Aubameyang to pick out the top-right corner.
But Ryan was alert. After four minutes, Aubameyang ran onto Matteo Guendouzi's ball over the top and tried to chip the Brighton keeper, who stretched to tip it away.
The Australia international then made an excellent low save to his right once Aubameyang was put clear through by Lucas Torreira's long pass and Brighton will miss him once he goes on Asian Cup duty throughout January, when he could be absent for seven games if Australia make the final.
At that stage, Brighton's only real chance was when Glenn Murray thought he had bundled in an equaliser after scuffing his first-time effort, but referee Anthony Taylor penalised the striker for a foul on Leno.
Yet once Arsenal showed how vulnerable they were defensively for Locadia's goal, Brighton attacked with increased confidence and came close to a late winner.
Captain Dale Stephens picked out March and then Locadia with two exquisite long passes in behind the Arsenal defence but the former lifted his chip well over the bar and the latter dragged his left-footed effort wide.
Man of the match - Mat Ryan (Brighton)
'We should've scored more early on' - reaction
Arsenal boss Unai Emery speaking to BBC Sport: "I'm a little disappointed. The first half was key in the match. We started winning and had another two chances, and they saved from Aubameyang.
"We didn't concede many chances but they drew level. In the second half we could not impose our gameplan. We did not make more clear chances to win the match.
"If we scored our chances in the first half we could have won."
Brighton boss Chris Hughton, speaking to BBC Sport: "It's always a good point but I'm really happy with the reaction of the team. If they got a second goal in that good period they had, it becomes a really hard afternoon.
"But we worked ourselves into a really good game and as the second half became more open, on the balance of play we looked more likely to score. Solly March's chance was the best of the game."
Arsenal's second-half scoring run ends - stats
- Arsenal have conceded in each of their last nine away Premier League games, only going longer without an away shut-out in the competition in a run of 11 ending in October 2010.
- Arsenal failed to score in the second half for the first time in their last 17 Premier League games, since losing to Chelsea on 18 August.
- Pierre-Emerick Aubameyang has been directly involved in 30 goals in his 32 Premier League appearances for Arsenal, scoring 23 and assisting seven.
- Since Aubameyang's debut for Arsenal in February, no duo has combined for more Premier League goals than the Gabon striker and Alexandre Lacazette (six, level with Bouremouth's Callum Wilson and Ryan Fraser and Tottenham's Harry Kane and Christian Eriksen).
- Brighton's Jurgen Locadia scored for the first time in his last 18 Premier League games, since scoring on his debut in the competition in February against Swansea City,
- Brighton have lost just two of their last 12 Premier League home games, winning five and drawing five.
Brighton host Everton on Saturday at 15:00 GMT before travelling to West Ham on Wednesday, 2 January at 19:45.
Arsenal face Liverpool at Anfield on Saturday at 17:30 and host London rivals Fulham on New Year's Day at 15:00.
- 22MontoyaBooked at 45mins
- 9LocadiaSubstituted forKnockaertat 86'minutes
- 17MurrayBooked at 58minsSubstituted forAndoneat 79'minutes
- 6KoscielnySubstituted forMaitland-Nilesat 70'minutes
- 31KolasinacBooked at 81mins
- 10ÖzilSubstituted forIwobiat 45'minutes
- 9LacazetteSubstituted forRamseyat 62'minutes
- Anthony Taylor
- Shots on Target
Second Half ends, Brighton and Hove Albion 1, Arsenal 1.
Corner, Arsenal. Conceded by Leon Balogun.
Attempt missed. Pascal Groß (Brighton and Hove Albion) header from the centre of the box misses to the right. Assisted by Bernardo.
Substitution, Brighton and Hove Albion. Anthony Knockaert replaces Jürgen Locadia.
Sead Kolasinac (Arsenal) is shown the yellow card.
Attempt missed. Jürgen Locadia (Brighton and Hove Albion) left footed shot from the left side of the box misses to the right. Assisted by Dale Stephens following a fast break.
Substitution, Brighton and Hove Albion. Florin Andone replaces Glenn Murray.
Attempt missed. Solly March (Brighton and Hove Albion) left footed shot from outside the box is too high. Assisted by Dale Stephens.
Corner, Arsenal. Conceded by Shane Duffy.
Lucas Torreira (Arsenal) wins a free kick in the attacking half.
Foul by Davy Pröpper (Brighton and Hove Albion).
Substitution, Arsenal. Ainsley Maitland-Niles replaces Laurent Koscielny.
Matteo Guendouzi (Arsenal) wins a free kick in the defensive half.
Foul by Davy Pröpper (Brighton and Hove Albion).
Foul by Lucas Torreira (Arsenal).
Bernardo (Brighton and Hove Albion) wins a free kick in the defensive half.
Corner, Arsenal. Conceded by Dale Stephens.
Substitution, Arsenal. Aaron Ramsey replaces Alexandre Lacazette.
Foul by Sokratis (Arsenal).